Abrasive article and method of forming same

ABSTRACT

An abrasive article may be configured to work titanium and may comprise a body including a bond material comprising an organic material. A first type of abrasive particles may be contained within the bond material and comprise fused alumina. The body may comprise a burnout modulus of rupture (MOR) of at least about 1.6 MPa.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application claims priority from U.S. Provisional PatentApplication No. 61/861,076, filed Aug. 1, 2013, entitled “ABRASIVEARTICLE AND METHOD OF FORMING SAME,” naming inventor Lingyu Li et al.,which application is incorporated by reference herein in its entirety.

BACKGROUND

1. Field of the Disclosure

The following is directed to abrasive articles, and particularly, bondedabrasive articles comprising abrasive particles of one or moreparticular types.

2. Description of the Related Art

Abrasive wheels are typically used for cutting, abrading, and shaping ofvarious materials, such as stone, metal, glass, plastics, among othermaterials. Generally, the abrasive wheels can have various phases ofmaterials including abrasive grains, a bonding agent, and some porosity.Depending upon the intended application, the abrasive wheel can havevarious designs and configurations. For example, for applicationsdirected to the finishing and cutting of metals, some abrasive wheelsare fashioned such that they have a particularly thin profile forefficient cutting.

However, given the application of such wheels, the abrasive articles aresubject to fatigue and failure. In fact, the wheels may have a limitedtime of use of less than a day depending upon the frequency of use.Accordingly, the industry continues to demand abrasive wheels capable ofimproved performance.

SUMMARY

An embodiment of an abrasive article may be configured to work titaniumand may comprise a body including a bond material. A first type ofabrasive particles may be contained within the bond material andcomprise fused alumina. A second type of abrasive particles may becontained within the bond material and comprise fused zirconia.

In some embodiments, a method of working titanium may include providinga workpiece comprising titanium. The method may further include moving abonded abrasive body relative to the workpiece to conduct a materialremoval process on the workpiece, wherein the bonded abrasive bodycomprises a relative material removal rate (MRR) improvement of at leastabout 5% for a standard titanium grinding test as compared to aconventional abrasive article.

An abrasive article may be configured to work titanium and include abody having a bond material comprising an organic material. A first typeof abrasive particles may be contained within the bond materialcomprising fused alumina. In addition, the body may include a burnoutelastic modulus (EMOD) of at least about 250 MPa.

In still another embodiment, an abrasive article configured to worktitanium may comprise a body including a bond material comprising anorganic material. A first type of abrasive particles may be containedwithin the bond material comprising fused alumina. The body may comprisea burnout modulus of rupture (MOR) of at least about 1.6 MPa.

In an alternate embodiment, an abrasive article configured to worktitanium may comprise a body including a bond material comprising aresin having a high temperature flexure modulus of at least 1.05. Afirst type of abrasive particle may be contained within the bondmaterial and may comprise fused alumina.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be better understood, and its numerousfeatures and advantages made apparent to those skilled in the art byreferencing the accompanying drawings.

FIG. 1 includes a plot of relative performance versus content of aparticular type of abrasive particle for the three specific conventionalsamples and specific samples representative of embodiments herein.

FIG. 2 includes a plot of relative material removal rate versus contentof a particular type of abrasive particle for three specificconventional samples and specific samples representative of embodimentsherein.

FIG. 3 includes a plot comparing the grain crush strength of an aluminaabrasive article to that of a zirconia abrasive article.

The use of the same reference symbols in different drawings indicatessimilar or identical items.

DETAILED DESCRIPTION

The following is directed to abrasive tools having abrasive particlescontained within a bond material for finishing, shaping, and/orconditioning workpieces. Certain embodiments herein are directed tobonded abrasive wheels, including large-diameter snagging wheels, thatmay be used for shaping of metal workpieces, including metals oftitanium or stainless steel. However, the features of the embodimentsherein may be applicable to other abrasive technologies, including forexample, coated abrasives and the like.

The abrasive article can be formed by forming a mixture of components orprecursor components that may be part of the final abrasive article. Forexample, the mixture can include components of the final abrasivearticle, such as abrasive particles, bond material, filler, and acombination thereof. In one embodiment, the mixture can include a firsttype of abrasive particle. A type of abrasive particle can be defined byat least a composition, a mechanical property (e.g., hardness,friability, etc.), particle size, a method of making, and a combinationthereof.

According to one embodiment, the first type of abrasive particles caninclude an oxide, and particularly, aluminum. For example, the firsttype of abrasive particles can include alumina. In one particularinstance, the first type abrasive particles can include fused alumina.In another instance, the first type abrasive particles can consistessentially of fused alumina. An exemplary type of fused alumina caninclude fused alumina 57A, commercially available from Washington Mills.

Regarding absolute values for single grain crush strength, the force (inNewtons) required to break the grains may be given in terms of thepercentage of the grains broken when subjected to breaking force. Forexample, about 220 N to about 280 N may be required to break 50% of thefirst type of abrasive particle. Thus, to break 50% of the first type ofabrasive particles at least about 220 N is required. Alternatively, atleast about 230 N, at least about 240 N, or even at least about 250 N isrequired to break 50% of the first type of abrasive particles. In stillother examples, no greater than about 1500 N is required to break 50% ofthe first type of abrasive particles. Alternatively, no greater thanabout 1000 N, or even no greater than about 500 N may be required tobreak 50% of the first type of abrasive particles. It will beappreciated that the first type of abrasive particle can have anabsolute crush strength within a range between any of the above notedminimum and maximum values. In these examples, the first type ofabrasive particles had an average size of about 6 grit.

In order to break 90% of the first type of abrasive particle about 300 Nto about 400 N of force may be required. Thus, to break 90% of the firsttype of abrasive particles, at least about 300 N, at least about 325 N,at least about 350 N, or no greater than about 2000 N, no greater thanabout 1500 N, no greater than about 1000 N, no greater than about 500 Nmay be required. It will be appreciated that the first type of abrasiveparticle can have an absolute crush strength within a range between anyof the above noted minimum and maximum values.

In terms of hardness, the first type of abrasive particle may have ahardness. For example, the first type of abrasive particle may have ahardness of at least about 15.7 GPa, at least about 16 GPa, at leastabout 16.5 GPa, or no greater than about 19 GPa, no greater than about18.5 GPa, no greater than about 18 GPa, no greater than about 17.5 GPa.It will be appreciated that the first type of abrasive particle can havea hardness within a range between any of the above noted minimum andmaximum values. For example, the first type of abrasive particle mayhave a hardness in a range of about 16.52 GPa to about 17.46 GPa.

According to one embodiment, the first type of abrasive particle canhave an average particle size of at least about 200 microns, such as atleast about 400 microns, at least about 600 microns, at least about 800microns, at least about 1000 microns, at least about 1500 microns, atleast about 2000 microns, at least about 2500 microns, at least about3000 microns, or even at least about 4000 microns. Still, in anothernon-limiting embodiment, the first type of abrasive particle can have anaverage particle size of not greater than about 3000 microns, such asnot greater than about 2500 microns, not greater than about 2000microns, not greater than about 1500 microns, or even not greater thanabout 1000 microns. It will be appreciated, that the average particlesize may be determined by measuring and averaging the longest dimension(i.e., the length) of the particles as viewed in two-dimensions (e.g.,SEM). The first type of abrasive particle can have an average particlesize within a range between any of the minimum and maximum values notedabove. For example, the first type of abrasive particle may have amedian particle size in a range of about 200 microns to about 5000microns (e.g., about 4 U.S. mesh to about 60 U.S. mesh).

The first type of abrasive particle can be made of crystalline grains.In particular instances, the first type of abrasive particle can have amedian grain size of about 4 U.S. mesh to about 60 U.S. mesh (e.g.,about 200 microns to about 5000 microns).

The abrasive particles of the mixture and the final-formed abrasivearticle may include more than one type of abrasive particle. Forexample, the mixture can include a second type of abrasive particledifferent than the first type of abrasive particle. The second type ofabrasive particle can differ from the first type of abrasive particle byany one of a composition, a mechanical property (e.g., hardness,friability, etc.), particle size, a method of making, or a combinationthereof.

According to one embodiment, the second type of abrasive particle canhave a different average particle size as compared to an averageparticle size of the first type of abrasive particle. For example, thesecond type of abrasive particle can have an average particle size thatis greater than the average particle size of the first type of abrasiveparticle. Still, in another embodiment, the second type of abrasiveparticle can have an average particle size that is less than the averageparticle size of the first type of abrasive particle.

In contrast to the first type of abrasive particle, about 1800 N toabout 2100 N may be required to break 50% of the second type of abrasivegrains. Thus, to break 50% of the second type of abrasive particles, atleast about 300 N, at least about 500 N, at least about 1000 N, or nogreater than about 2400 N, no greater than about 2300 N, no greater thanabout 220 N may be required. It will be appreciated that the second typeof abrasive particle can have an absolute crush strength within a rangebetween any of the above noted minimum and maximum values.

In order to break 90% of the second type of abrasive particles about2300 N to about 2900 N of force may be required. Thus, to break 90% ofthe second type of abrasive particles, at least about 500 N, at leastabout 1000 N, at least about 1500 N, at least about 2000 N, or nogreater than about 3300 N, no greater than about 3200 N, no greater thanabout 3100 N, no greater than about 3000 N may be required. It will beappreciated that the second type of abrasive particle can have anabsolute crush strength within a range between any of the above notedminimum and maximum values.

Relative friability between the first and second types of abrasiveparticles may be defined as follows:

[(N _(G2) −N _(G1))/N _(G1)]×100%

wherein N_(G1) is the amount of force (e.g., in newtons) required tobreak a single grain of a first type of abrasive particle and N_(G2) isthe amount of force required to break a single grain of a second type ofabrasive particle. These forces may be derived from, for example, aWeibull probability plot of grain crush strength, such as the onedisclosed in FIG. 3.

In some embodiments, the first type of abrasive particle is at leastabout 50% more friable than the second type of abrasive particle. Inother embodiments, the first type of abrasive particle may be about 60%more friable than the second type of abrasive particle, about 70% morefriable, about 80% more friable, about 90% more friable than the secondtype of abrasive particle. In still other embodiments, the first type ofabrasive particle is not greater than 200% more friable than the firsttype of abrasive particle. For example, the first type of abrasiveparticle may be not greater than 150% more friable than the second typeof abrasive particle, not greater than 125%, not greater than 100%, notgreater than 98%, not greater than 96%, or even not greater than 94%than the second type of abrasive particle. It will be appreciated thatthe abrasive particle may have a friability within a range between anyof the above noted minimum and maximum percentages.

In terms of hardness, the second type of abrasive particle may have ahardness of at least about 14 GPa, at least about 14.25 GPa, at leastabout 14.5 GPa, or no greater than about 16.5 GPa, no greater than about16.25 GPa, no greater than about 16 GPa, no greater than about 15.75GPa. It will be appreciated that the second type of abrasive particlecan have a hardness within a range between any of the above notedminimum and maximum values. For example, the second type of abrasiveparticle may have a hardness in a range of about 14.79 GPa to about15.65 GPa.

Relative hardness between the first and second types of abrasiveparticles may be defined as follows:

[(H _(G1) −H _(G2))/H _(G2)]×100%

wherein H_(G1) is the hardness of a first type of abrasive particle andH_(G2) is the hardness of a second type of abrasive particle. In someembodiments, the first type of abrasive particle may be about 1% harderthan the second type of abrasive particle, about 3% harder, about 5%harder, about 10% harder than the second type of abrasive particle. Instill other embodiments, the first type of abrasive particle is notgreater than 30% harder than the first type of abrasive particle. Forexample, the first type of abrasive particle may be not greater than 25%harder than the second type of abrasive particle, not greater than 20%,not greater than 18%, or even not greater than 16% harder than thesecond type of abrasive particle. It will be appreciated that theabrasive particles may have a hardness within a range between any of theabove noted minimum and maximum percentages.

In certain instances, the second type of abrasive particle can have anaverage particle size of at least about 200 microns, such as at leastabout 400 microns, at least about 600 microns, at least about 800microns, at least about 1000 microns, at least about 1500 microns, atleast about 2000 microns, at least about 2500 microns, at least about3000 microns, or even at least about 4000 microns. Still, in anothernon-limiting embodiment, the second type of abrasive particle can havean average particle size of not greater than about 3000 microns, such asnot greater than about 2500 microns, not greater than about 2000microns, not greater than about 1500 microns, or even not greater thanabout 1000 microns. The second type of abrasive particle can have anaverage particle size within a range between any of the minimum andmaximum values noted above. For example, the second type of abrasiveparticle may have a median particle size in a range of about 200 micronsto about 5000 microns (e.g., about 4 U.S. mesh to about 60 U.S. mesh).

According to an embodiment, the second type of abrasive particle caninclude an oxide, and particularly, an oxide such as alumina, zirconia,and a combination thereof. In at least one embodiment, the second typeof abrasive particle can consist essentially of zirconia and alumina.For certain instances, the second type of abrasive particle can includealumina and zirconia, and can have a greater content of alumina ascompared to a content of zirconia. For example, the second type ofabrasive particle can contain a majority content of alumina and aminority content of zirconia. In one exemplary embodiment, the secondtype of abrasive particle can include an alumina-zirconia compositeparticle comprising approximately 75% alumina and 25% zirconia,commercially available as ZF/ZS grains from Saint-Gobain Grains andPowders. More particularly, the second type of abrasive particle canconsist essentially of an alumina-zirconia abrasive particle.

According to one particular embodiment, the second type of abrasiveparticle can include at least about 60% alumina for the totalcomposition of the abrasive particle. Moreover, in certain otherinstances, the content of alumina can be greater, such as at least about70%, and even at least about 75%. Still, in another non-limitingembodiment, the amount of alumina present in the second type of abrasiveparticle can be not greater than about 98%, such as not greater thanabout 95%, not greater than about 90%, or even not greater than about85%. The second type of abrasive particle can have an alumina contentwithin a range between any of the minimum and maximum percentages notedabove.

The second type of abrasive particle may contain a particular content ofzirconia. For example, the second type of abrasive particle can includeat least about 5% zirconia, such as at least about 10% zirconia, or evenat least about 15% zirconia for the total content of components make upthe composition of the abrasive particle. Still, in another non-limitingembodiment, the amount of zirconia present in the second type ofabrasive particle can be not greater than about 40% zirconia, such asnot greater than about 35% zirconia, not greater than about 30%zirconia, or even not greater than about 25% zirconia. The second typeof abrasive particle can have a zirconia content within a range betweenany of the minimum and maximum percentages noted above.

The mixture and the body of the finally formed abrasive article maycomprise a certain blend of the first type of abrasive particle and asecond type of abrasive particle. For example, the blend can include adifferent amount (vol %) of the first type of abrasive particle than anamount (vol %) of the second type of abrasive particle as measured bythe weight of the mixture or the weight of the body of the abrasivearticle. In certain cases, the blend can include a greater amount of thefirst type of abrasive particles than the amount of the second type ofabrasive particles.

In one instance, the blend may be defined by a ratio (AP1/AP2) of atleast about 0.01, wherein AP1 represents an amount of first type ofabrasive particles in the blend and AP2 represents an amount of thesecond type of abrasive particles in the blend. The amount may bemeasured as the weight or weight percent of each of the respective typesof abrasive particle. In one embodiment, the ratio (AP1/AP2) may be atleast about 0.05, such as at least about 0.08, at least about 0.1, atleast about 0.12, at least about 0.14, or even at least about 0.16.Still, in one other non-limiting embodiment, the ratio (AP1/AP2) may benot greater than about 4, such as not greater than about 3, such as notgreater than about 2, not greater than about 1.5, not greater than about1, not greater than about 0.9, not greater than about 0.7, not greaterthan about 0.6, not greater than about 0.5, or even not greater thanabout 0.4. The ratio can be within a range between any of the minimumand maximum values noted above.

The abrasive particles of any type may have an elongated shaped. In aparticular instance, the abrasive particles may have an aspect ratio,defined as a ratio of the length:width, of at least about 2:1, whereinthe length is the longest dimension of the particle and the width is thesecond longest dimension of the particle (or diameter) perpendicular tothe dimension of the length as viewed in two dimensions. In otherembodiments, the aspect ratio of the abrasive particles can be at leastabout 2.5:1, such as at least about 3:1, at least about 4:1, at leastabout 5:1, or even at least about 10:1. In one non-limiting embodiment,the abrasive particles may have an aspect ratio of not greater thanabout 5000:1. Still, it will be appreciated, that in other embodiments,the abrasive particles of any type can be generally equiaxed having anaspect ratio of substantially 1:1. In yet another embodiment, theabrasive particles of any type can have an irregular shape.

In at least one embodiment, the abrasive particles (of any type) canhave a particular cross-sectional shape as viewed in two dimensions. Forexample, the abrasive particles can have an ellipsoidal cross-sectionalshape. An ellipsoidal shape can include circles, ellipses, and any othercurvilinear shapes. Alternatively, in other instances, the abrasiveparticles can have a polygonal cross-sectional shape. Some suitable,non-limiting, examples of polygonal cross-sectional shapes includetriangular, rectangular, pentagonal, hexagonal, heptagonal, octagonal,and the like.

As described herein, in addition to the abrasive particles, the mixturemay also include other components or precursors to facilitate formationof the abrasive article. For example, the mixture may include abrasiveparticles and a bond material. According to one embodiment, the bondmaterial may include a material selected from the group consisting of anorganic material, an organic precursor material, an inorganic material,an inorganic precursor material, a natural material, and a combinationthereof. In particular instances, the bond material may include a metalor metal alloy, such as a powder metal material, or a precursor to ametal material, suitable for formation of a metal bond matrix materialduring further processing.

According to another embodiment, the mixture may include a vitreousmaterial, or a precursor of a vitreous material, suitable for formationof a vitreous bond material during further processing. For example, themixture may include a vitreous material in the form of a powder,including for example, an oxygen-containing material, an oxide compoundor complex, a frit, and any combination thereof.

In yet another embodiment, the mixture may include a ceramic material,or a precursor of a ceramic material, suitable for formation of aceramic bond material during further processing. For example, themixture may include a ceramic material in the form of a powder,including for example, an oxygen-containing material, an oxide compoundor complex, and any combination thereof.

According to another embodiment, the mixture may include an organicmaterial, or a precursor of an organic material, suitable for formationof an organic bond material during further processing. Such an organicmaterial may include one or more natural organic materials, syntheticorganic materials, and a combination thereof. In particular instances,the organic material can be made of a resin, which may include athermoset, a thermoplastic, and a combination thereof. According to oneembodiment, the bond material can include an organic material selectedfrom the group of epoxy resins, polyester resins, polyurethanes,polyester, rubber, polyimide, polybenzimidazole, aromatic polyamide,modified phenolic resins, and a combination thereof. In one particularcase, the bond can consist essentially of a resin. Some suitable resinscan include phenolics, epoxies, polyesters, cyanate esters, shellacs,polyurethanes, rubber, and a combination thereof. In one particularembodiment, the mixture includes an uncured resin material configured toform a phenolic resin bond material through further processing.

Other materials, such as a filler, can be included in the mixture. Thefiller may or may not be present in the finally-formed abrasive article.The filler may include a material selected from the group consisting ofpowders, granules, spheres, fibers, and a combination thereof. Moreover,in particular instances, the filler can include an inorganic material,an organic material, and a combination thereof. In a certain embodiment,the filler can include a material such as sand, bubble alumina, bauxite,chromites, magnesite, dolomites, bubble mullite, borides, titaniumdioxide, carbon products (e.g., carbon black, coke or graphite), siliconcarbide, wood flour, clay, talc, hexagonal boron nitride, molybdenumdisulfide, feldspar, nepheline syenite, glass spheres, glass fibers,CaF2, KBF4, Cryolite (Na₃AlF₆), potassium Cryolite (K₃AlF₆), pyrites,ZnS, copper sulfide, mineral oil, fluorides, carbonates, calciumcarbonate, and a combination thereof, wherein the filler comprises amaterial selected from the group consisting of an antistatic agent, alubricant, a porosity inducer, coloring agent, and a combinationthereof. In particular instances wherein the filler is particulatematerial, it may be distinct from the abrasive particles, beingsignificantly smaller in average particle size than the abrasiveparticles of any type.

After forming the mixture, the process of forming the abrasive articlecan further include forming a green body comprising abrasive particlescontained in a bond material. A green body is a body that is unfinishedand may undergo further processing before a finally-formed abrasivearticle is formed. Forming of the green body can include techniques suchas pressing, molding, casting, printing, spraying, and a combinationthereof. In one particular embodiment, forming of the green body caninclude pressing the mixture into a particular shape, including forexample, conducting a cold isostatic pressing operation to form a greenbody in the desired form of the body.

After forming the green body, the process can continue by treating thegreen body to form a finally-formed abrasive article comprising a body.Some suitable examples of treating can include curing, heating,sintering, crystallizing, polymerization, pressing, and a combinationthereof. In one example, the process may include bond batching, mixingabrasive with bond, filling a mold, pressing, wheel baking or curing,finishing, inspection, speed testing, and packing and shipping

The abrasive articles of the embodiments herein can have a body that maybe in the form of a bonded abrasive. The body can have various shapes,including for example, a hone, a cone, a cup, flanged shapes, acylinder, a wheel, a ring, and a combination thereof. In one particularembodiment, the body can be a bonded abrasive snagging wheel.

After treating, the abrasive article can be formed to have a bodyincluding a particular content of bond material. For example, the bodycan have at least about 25 vol % bond material for the total volume ofthe body. In other instances, the content of bond material in the bodycan be greater, such as at least about 30 wt %, at least about 35 wt %,at least about 40 wt %, at least about 45 vol %, at least about 50 vol%, at least about 55 vol %, or even at least about 60 vol %. Still, inat least one non-limiting embodiment, the content of bond material inthe body can be not greater than about 70 vol %, such as not greaterthan about 65 vol %, not greater than about 60 vol %, not greater thanabout 55 vol %, not greater than about 50 vol %, not greater than about45 vol %, not greater than about 40 vol %, not greater than about 35 vol%, or even not greater than about 30 vol %. It will be appreciated thatthe content of bond material in the body can be within a range betweenany of the minimum and maximum percentages noted above.

According to one embodiment, the bond material of the body can include aresin, and particularly a phenolic resin. In some embodiments, the resinmay have a high temperature flexure modulus of at least 1.05.Alternatively, the resin may have an increasing high temperatureflexural modulus. The phenolic resin may be modified with a curing orcross-linking agent, such as hexamethylene tetramine. At temperatures inexcess of about 90° C., some examples of the hexamethylene tetramine mayform crosslinks to form methylene and dimethylene amino bridges thathelp cure the resin. The hexamethylene tetramine may be uniformlydispersed within the resin. More particularly, hexamethylene tetraminemay be uniformly dispersed within resin regions as a cross-linkingagent. Even more particularly, the phenolic resin may contain resinregions with cross-linked domains having a sub-micron average size.

According to one embodiment, the body can have a particular content ofporosity. For example, the body can have not greater than about 10 vol %porosity for the total volume of the body. In a particular instance, thebody can have not greater than about 9 vol %, such as not greater thanabout 8 vol %, not greater than about 7 vol %, not greater than about 6vol %, not greater than about 5 vol %, not greater than about 4 vol %,not greater than about 3 vol %, or even not greater than about 2 vol %.According to one non-limiting embodiment, the body can have zeroporosity, or at least about 0.05 vol % porosity. In certain otherinstances, the body can have a porosity of at least about 0.5 vol %, atleast about 1 vol %, at least about 2 vol %, at least about 3 vol %, atleast about 4 vol %, at least about 5 vol %, at least about 6 vol %, atleast about 7 vol %, or even at least about 8 vol %. It will beappreciated that the porosity of the body can be within a range betweenany of the minimum and maximum percentages noted above.

For certain abrasive articles of the embodiments herein, the body canhave a particular total content of abrasive particles, which includesthe total amount of all types of abrasive particles. For example, in oneembodiment, the body can include at least about 30 vol % abrasiveparticles for the total volume of the body. In another embodiment, thebody can have at least about 35 vol %, at least about 40 vol %, at leastabout 45 vol %, at least about 50 vol %, at least about 55 vol %, atleast about 60 vol %, at least about 65 vol %, or even at least about 70vol % abrasive particles. In at least one non-limiting embodiment, thebody can have a content of abrasive particles of not greater than about75 vol %, such as not greater than about 70 vol %, not greater thanabout 65 vol %, not greater than about 60 vol %, not greater than about50 vol %, not greater than about 45 vol %, not greater than about 40 vol%, or even not greater than about 35 vol %. It will be appreciated thatthe total content of abrasive particles in the body can be within arange between any of the minimum and maximum percentages noted above.

Moreover, the body of the abrasive article may have a particular contentof the first type of abrasive particle. For example, in one embodiment,the body can include at least about 1 vol % of the first type ofabrasive particle for the total volume of the body. In anotherembodiment, the body can have at least about 5 vol %, at least about 10vol %, at least about 15 vol %, at least about 20 vol %, at least about25 vol %, at least about 30 vol %, at least about 35 vol %, at leastabout 40 vol %, or even at least about 45 vol % of the first type ofabrasive particle. In at least one non-limiting embodiment, the body canhave a content of the first type of abrasive particle of not greaterthan about 50 vol %, such as not greater than about 45 vol %, notgreater than about 40 vol %, not greater than about 35 vol %, notgreater than about 30 vol %, not greater than about 25 vol %, notgreater than about 20 vol %, not greater than about 15 vol %, notgreater than about 10 vol %, not greater than about 5 vol %, or even notgreater than about 2 vol %. It will be appreciated that the totalcontent of the first type of abrasive particle in the body can be withina range between any of the minimum and maximum percentages noted above.

The body of the abrasive article may have a particular content of thesecond type of abrasive particle. For example, in one embodiment, thebody can include at least about 1 vol % of the first type of abrasiveparticle for the total volume of the body. In another embodiment, thebody can have at least about 5 vol %, at least about 10 vol %, at leastabout 15 vol %, at least about 20 vol %, at least about 25 vol %, atleast about 30 vol %, at least about 35 vol %, at least about 40 vol %,or even at least about 45 vol % of the first type of abrasive particle.In at least one non-limiting embodiment, the body can have a content ofthe second type of abrasive particle of not greater than about 50 vol %,such as not greater than about 45 vol %, not greater than about 40 vol%, not greater than about 35 vol %, not greater than about 30 vol %, notgreater than about 25 vol %, not greater than about 20 vol %, notgreater than about 15 vol %, not greater than about 10 vol %, notgreater than about 5 vol %, or even not greater than about 2 vol %. Itwill be appreciated that the total content of the second type ofabrasive particle in the body can be within a range between any of theminimum and maximum percentages noted above.

According to one embodiment, the abrasive article may be particularlysuited for grinding and conditioning of workpieces, which may includeprocesses such as cutting, grinding, finishing, and a combinationthereof. Certain suitable workpieces can include inorganic materials,and more particularly workpieces made of a metal or metal alloy.According to one embodiment, the abrasive article may be particularlysuited to grind materials such as titanium or steel.

In an embodiment, the body can have a particular burnout modulus ofrupture (MOR). The burnout procedure included placing three bars persample (or specification) in an oven once the oven reached 450° C. Eachbar measured 1″×0.5″×5″. The samples were burned at 450° C. for 4 hoursand then allowed to cool inside the oven. The measurements were taken atroom temperature conditions. According to one aspect, the body can havea burnout MOR of at least about 1.6 MPa. In still other instances, theburnout MOR can be at least about 1.7 MPa, such as at least about 1.8MPa, at least about 1.9 MPa, at least about 2 MPa, at least about 2.1MPa, or even at least about 2.2 MPa. In one non-limiting embodiment, theburnout MOR can be not greater than about 10 MPa, such as not greaterthan about 8 MPa. It will be appreciated that the burnout MOR of thebody can be within a range between any of the minimum and maximum valuesnoted above.

According to another aspect, the body can have a particular burnoutelastic modulus (EMOD). The burnout procedure included placing threebars per sample (or specification) in an oven once the oven reached 450°C. Each bar measured 1″×0.5″×5″. The samples were burned at 450° C. for4 hours and then allowed to cool inside the oven. The measurements weretaken at room temperature conditions. According to one aspect, the bodycan have a burnout EMOD of at least about 250 MPa. In still otherinstances, the burnout EMOD can be at least about 270 MPa, at leastabout 300 MPa, at least about 325 MPa, at least about 350 MPa, at leastabout 375 MPa, at least about 400 MPa, at least about 425 MPa, or evenat least about 450 MPa. In one non-limiting embodiment, the burnout EMODcan be not greater than about 1000 MPa, such not greater than about 800MPa. It will be appreciated that the burnout EMOD of the body can bewithin a range between any of the minimum and maximum values notedabove.

Items

Item 1. An abrasive article configured to work titanium comprising: abody including: a bond material comprising a resin having a hightemperature flexure modulus of at least 1.05; and a first type ofabrasive particles contained within the bond material comprising fusedalumina.

Item 2. The abrasive article of item 1, wherein the first type abrasiveparticles consist essentially of fused alumina.

Item 3. The abrasive article of item 1, wherein the first type ofabrasive particle comprises an average particle size of at least about200 microns, at least about 400 microns, at least about 600 microns, atleast about 800 microns, at least about 1000 microns, at least about1500 microns, at least about 2000 microns, at least about 2500 microns,at least about 3000 microns, at least about 4000 microns, not greaterthan about 3000 microns, not greater than about 2500 microns, notgreater than about 2000 microns, not greater than about 1500 microns,not greater than about 1000 microns.

Item 4. The abrasive article of item 1, further comprising a second typeof abrasive particle different than the first type of abrasive particle,wherein the first type of abrasive particle is more friable than thesecond type of abrasive particle.

Item 5. The abrasive article of item 4, wherein the second type ofabrasive particle comprises an average particle size of at least about200 microns, at least about 400 microns, at least about 600 microns, atleast about 800 microns, at least about 1000 microns, at least about1500 microns, at least about 2000 microns, at least about 2500 microns,at least about 3000 microns, at least about 4000 microns, not greaterthan about 3000 microns, not greater than about 2500 microns, notgreater than about 2000 microns, not greater than about 1500 microns,not greater than about 1000 microns.

Item 6. The abrasive article of item 4, wherein the second type ofabrasive particle comprises alumina, wherein the second type of abrasiveparticle comprises zirconia, wherein the second type of abrasiveparticle comprises zirconia and alumina, wherein the second type ofabrasive particle consists essentially of zirconia and alumina, whereinthe second type of abrasive particle comprises a greater content ofalumina as compared to a content of zirconia, wherein the second type ofabrasive particle comprises a majority content of alumina and a minoritycontent of zirconia, wherein the second type of abrasive particlecomprises at least about 60% alumina, at least about 70% alumina, atleast about 75% alumina, and not greater than about 98% alumina, notgreater than about 95% alumina, not greater than about 90% alumina, notgreater than about 85% alumina, at least about 5% zirconia, at leastabout 10% zirconia, at least about 15% zirconia, and not greater thanabout 40% zirconia, not greater than about 35% zirconia, not greaterthan about 30% zirconia, not greater than about 25% zirconia.

Item 7. The abrasive article of item 1, wherein the body comprise ablend of the first type of abrasive particles and a second type ofabrasive particles different than the first type of abrasive particles,wherein the blend comprises a different amount (vol %) of the first typeof abrasive particle than an amount (vol %) of the second type ofabrasive particles, wherein the blend comprises a greater amount of thefirst type of abrasive particles than the amount of the second type ofabrasive particles, wherein the blend comprises a ratio (AP1/AP2) of atleast about 0.01 and not greater than about 4, wherein AP1 representsthe weight of first type of abrasive particles in the blend and AP2represents the weight of the second type of abrasive particles in theblend, at least about 0.05, at least about 0.08, at least about 0.1, atleast about 0.12, at least about 0.14, at least about 0.16, and notgreater than about 3, not greater than about 2, not greater than about1.5, not greater than about 1, not greater than about 0.9, not greaterthan about 0.7, not greater than about 0.6, not greater than about 0.5,not greater than about 0.4.

Item 8. The abrasive article of item 1, wherein the body comprises atotal content of abrasive particles of not greater than about 75 vol %for the total volume of the body, not greater than about 70 vol %, notgreater than about 65 vol % not greater than about 60 vol %, not greaterthan about 55 vol %, not greater than about 50 vol % not greater thanabout 45 vol %, not greater than about 40 vol %, not greater than about35 vol %, and at least about 30 vol %, at least about 35 vol %, at leastabout 40 vol %, at least about 45 vol %, at least about 50 vol %, atleast about 55 vol %, at least about 60 vol %, at least about 65 vol %.

Item 9. The abrasive article of item 1, wherein the body comprises atotal content of bond material of not greater than about 70 vol % forthe total volume of the body, not greater than about 65 vol %, notgreater than about 60 vol % not greater than about 55 vol %, not greaterthan about 50 vol %, not greater than about 45 vol % not greater thanabout 40 vol %, not greater than about 35 vol %, not greater than about30 vol %, and at least about 25 vol %, at least about 30 vol %, at leastabout 35 vol %, at least about 40 vol %, at least about 45 vol %, atleast about 50 vol %, at least about 55 vol %, at least about 60 vol %,at least about 65 vol %.

Item 10. The abrasive article of item 1, wherein the body comprisesporosity, wherein the body comprises a total content of porosity of notgreater than about 10 vol % porosity for a total volume of the body, notgreater than about 9 vol %, not greater than about 8 vol %, not greaterthan about 7 vol %, not greater than about 6 vol %, not greater thanabout 5 vol %, not greater than about 4 vol %, not greater than about 3vol %, not greater than about 2 vol %, at least about 0.05 vol %porosity, at least about 0.5 vol %, at least about 1 vol %, at leastabout 2 vol %, at least about 3 vol %, at least about 4 vol %, at leastabout 5 vol %, at least about 6 vol %, at least about 7 vol %, at leastabout 8 vol %.

Item 11. The abrasive article of item 1, wherein the bond materialcomprises a material selected from the group consisting of an inorganicmaterial, an organic material, and a combination thereof, wherein thebond material comprises an organic material selected from the groupconsisting of epoxy resins, polyester resins, polyurethanes, polyester,rubber, polyimide, polybenzimidazole, aromatic polyamide, modifiedphenolic resins, and a combination thereof, wherein the bond consistsessentially of a resin.

Item 12. The abrasive article of item 1, wherein the body furthercomprises a filler, wherein the bond material further comprises a fillermaterial, wherein the filler comprises a material selected from thegroup consisting of powders, granules, spheres, fibers, and acombination thereof, wherein the filler comprises a material selectedfrom the group consisting of an inorganic material, an organic material,and a combination thereof, wherein the filler comprises a materialselected from the group consisting of sand, bubble alumina, bauxite,chromites, magnesite, dolomites, bubble mullite, borides, titaniumdioxide, carbon products (e.g., carbon black, coke or graphite), woodflour, clay, talc, hexagonal boron nitride, molybdenum disulfide,feldspar, nepheline syenite, glass spheres, glass fibers, CaF₂, KBF₄,Cryolite (Na₃AlF₆), potassium Cryolite (K₃AlF₆), pyrites, ZnS, coppersulfide, mineral oil, fluorides, carbonates, calcium carbonate, and acombination thereof, wherein the filler comprises a material selectedfrom the group consisting of an antistatic agent, a metal oxide, alubricant, a porosity inducer, coloring agent, and a combinationthereof.

Item 13. The abrasive article of item 1, wherein the body is configuredto conduct a material removal operation on a workpiece comprisingtitanium, wherein the material removal operation is selected from thegroup consisting of cutting, grinding, finishing, and a combinationthereof.

Item 14. The abrasive article of item 1, wherein the body comprises aburnout modulus of rupture (MOR) of at least about 1.6 MPa, at leastabout 1.7 MPa, at least about 1.8 MPa, at least about 1.9 MPa, at leastabout 2 MPa, at least about 2.1 MPa, at least about 2.2 MPa, and notgreater than about 10 MPa, not greater than about 8 MPa.

Item 15. The abrasive article of item 1, wherein the body comprises aburnout elastic modulus (EMOD) of at least about 250 MPa, at least about270 MPa, at least about 300 MPa, at least about 325 MPa, at least about350 MPa, at least about 375 MPa, at least about 400 MPa, at least about425 MPa, at least about 450 MPa, and not greater than about 1000 MPa,not greater than about 800 MPa.

Item 16. The abrasive article of item 1, wherein the body comprises arelative material removal rate (MRR) improvement of at least about 5%for a standard titanium grinding test as compared to a conventionalabrasive article, at least about 8%, at least about 10%, at least about12%, at least about 15%, and not greater than about 80%, not greaterthan about 50%, not greater than about 40%.

Item 17. The abrasive article of item 1, wherein the body comprises arelative life improvement of at least about 5% for a standard titaniumgrinding test as compared to a conventional abrasive article, at leastabout 8%, at least about 10%, at least about 12%, at least about 15%,and not greater than about 80%, not greater than about 50%, not greaterthan about 40%.

Item 18. The abrasive article of item 4, wherein the first type ofabrasive particle is at least about 50% more friable than the secondtype of abrasive particle, about 60% more friable, about 70% morefriable, about 80% more friable, and not greater than 150% more friablethan the second type of abrasive particle, not greater than 125%, notgreater than 100%.

Item 19. The abrasive article of item 1, wherein, to break 50% of thefirst type of abrasive particles, at least about 220 N is required, atleast about 230 N, at least about 240 N, at least about 250 N, or nogreater than about 1500 N, no greater than about 1000 N, no greater thanabout 500 N.

Item 20. The abrasive article of item 4, wherein, to break 50% of thesecond type of abrasive particles, at least about 300 N, at least about500 N, at least about 1000 N, or no greater than about 2400 N, nogreater than about 2300 N, no greater than about 2200 N is required.

Item 21. The abrasive article of item 1, wherein, to break 90% of thefirst type of abrasive particles, at least about 300 N, at least about325 N, at least about 350 N, or no greater than about 2000 N, no greaterthan about 1500 N, no greater than about 500 N is required.

Item 22. The abrasive article of item 4, wherein, to break 90% of thesecond type of abrasive particles, at least about 500 N, at least about750 N, at least about 1000 N, at least about 1500 N, or no greater thanabout 3300 N, no greater than about 3200 N, no greater than about 3100N, no greater than about 3000 N is required.

Item 23. The abrasive article of item 1, wherein the first type ofabrasive particle has a hardness of at least about 15.7, at least about16, at least about 16.5, no greater than about 19, no greater than about18.5, no greater than about 18, no greater than about 17.5.

Item 24. The abrasive article of item 4, wherein the second type ofabrasive has a hardness of at least about 14, at least about 14.25, atleast about 14.5, or no greater than about 16.5, no greater than about16.25, no greater than about 16, no greater than about 15.75.

Item 25. The abrasive article of item 4, wherein the first type ofabrasive particle is about 1% harder than the second type of abrasiveparticle, about 3% harder, about 5% harder, about 10% harder than thesecond type of abrasive particle, not greater than 30% harder than thefirst type of abrasive particle, not greater than 25%, not greater than20%, not greater than 18%, not greater than 16% harder than the secondtype of abrasive particle.

Item 26. An abrasive article configured to work titanium comprising: abody including: a bond material comprising an organic material; a firsttype of abrasive particles contained within the bond material comprisingfused alumina; and wherein the body comprises a burnout modulus ofrupture (MOR) of at least about 1.6 MPa.

Item 27. The abrasive article of item 26, wherein the first typeabrasive particles consist essentially of fused alumina.

Item 28. The abrasive article of item 26, wherein the first type ofabrasive particle comprises an average particle size of at least about500 microns and not greater than about 3000 microns.

Item 29. The abrasive article of item 26, further comprising a secondtype of abrasive particle different than the first type of abrasiveparticle, wherein the second type of abrasive particle comprises adifferent average particle size as compared to an average particle sizeof the first type of abrasive particle.

Item 30. The abrasive article of item 29, wherein the second type ofabrasive particle comprises an average particle size of at least about500 microns and not greater than about 3000 microns.

Item 31. The abrasive article of item 29, wherein the second type ofabrasive particle comprises zirconia and alumina.

Item 32. The abrasive article of item 26, wherein the body comprise ablend of the first type of abrasive particles and a second type ofabrasive particles different than the first type of abrasive particles,wherein the blend comprises a different amount (vol %) of the first typeof abrasive particle than an amount (vol %) of the second type ofabrasive particles, wherein the blend comprises a greater amount of thefirst type of abrasive particles than the amount of the second type ofabrasive particles, wherein the blend comprises a ratio (AP1/AP2) of atleast about 0.01 and not greater than about 4.

Item 33. The abrasive article of item 26, wherein the body comprises atotal content of abrasive particles of not greater than about 75 vol %for the total volume of the body, and at least about 30 vol %.

Item 34. The abrasive article of item 26, wherein the body comprises atotal content of bond material of not greater than about 70 vol % forthe total volume of the body, and at least about 25 vol %.

Item 35. The abrasive article of item 26, wherein the body comprisesporosity, wherein the body comprises a total content of porosity of notgreater than about 10 vol % for the total volume of the body, and atleast about 1 vol %.

Item 36. The abrasive article of item 26, wherein the bond materialcomprises a material selected from the group consisting of an inorganicmaterial, an organic material, and a combination thereof, wherein thebond material comprises an organic material selected from the groupconsisting of epoxy resins, polyester resins, polyurethanes, polyester,rubber, polyimide, polybenzimidazole, aromatic polyamide, modifiedphenolic resins, and a combination thereof, wherein the bond consistsessentially of a resin.

Item 37. The abrasive article of item 26, wherein the body furthercomprises a filler.

Item 38. The abrasive article of item 26, wherein the body is configuredto conduct a material removal operation on a workpiece comprisingtitanium, wherein the material removal operation is selected from thegroup consisting of cutting, grinding, finishing, and a combinationthereof.

Item 39. The abrasive article of item 26, wherein the burnout modulus ofrupture (MOR) of at least about 1.7 MPa, at least about 1.8 MPa, atleast about 1.9 MPa, at least about 2 MPa, at least about 2.1 MPa, atleast about 2.2 MPa, and not greater than about 10 MPa, not greater thanabout 8 MPa.

Item 40. The abrasive article of item 26, wherein the body comprises aburnout elastic modulus (EMOD) of at least about 250 MPa, at least about270 MPa, at least about 300 MPa, at least about 325 MPa, at least about350 MPa, at least about 375 MPa, at least about 400 MPa, at least about425 MPa, at least about 450 MPa, and not greater than about 1000 MPa,not greater than about 800 MPa.

Item 41. The abrasive article of item 29, wherein the first type ofabrasive particle is at least about 50% more friable than the secondtype of abrasive particle, about 60% more friable, about 70% morefriable, about 80% more friable, and not greater than 150% more friablethan the second type of abrasive particle, not greater than 125%, notgreater than 100%.

Item 42. The abrasive article of item 26, wherein, to break 50% of thefirst type of abrasive particles, at least about 220 N is required, atleast about 230 N, at least about 240 N, at least about 250 N, or nogreater than about 1500 N, no greater than about 1000 N, no greater thanabout 500 N.

Item 43. The abrasive article of item 29, wherein, to break 50% of thesecond type of abrasive particles, at least about 300 N, at least about500 N, at least about 1000 N, or no greater than about 2400 N, nogreater than about 2300 N, no greater than about 2200 N is required.

Item 44. The abrasive article of item 26, wherein, to break 90% of thefirst type of abrasive particles, at least about 300 N, at least about325 N, at least about 350 N, or no greater than about 2000 N, no greaterthan about 1500 N, no greater than about 500 N is required.

Item 45. The abrasive article of item 29, wherein, to break 90% of thesecond type of abrasive particles, at least about 500 N, at least about750 N, at least about 1000 N, at least about 1500 N, or no greater thanabout 3300 N, no greater than about 3200 N, no greater than about 3100N, no greater than about 3000 N is required.

Item 46. The abrasive article of item 26, wherein the first type ofabrasive particle has a hardness of at least about 15.7, at least about16, at least about 16.5, no greater than about 19, no greater than about18.5, no greater than about 18, no greater than about 17.5.

Item 47. The abrasive article of item 29, wherein the second type ofabrasive has a hardness of at least about 14, at least about 14.25, atleast about 14.5, or no greater than about 16.5, no greater than about16.25, no greater than about 16, no greater than about 15.75.

Item 48. The abrasive article of item 29, wherein the first type ofabrasive particle is about 1% harder than the second type of abrasiveparticle, about 3% harder, about 5% harder, about 10% harder than thesecond type of abrasive particle, not greater than 30% harder than thefirst type of abrasive particle, not greater than 25%, not greater than20%, not greater than 18%, not greater than 16% harder than the secondtype of abrasive particle.

Item 49. An abrasive article configured to work titanium comprising: abody including: a bond material comprising an organic material; a firsttype of abrasive particles contained within the bond material comprisingfused alumina; and wherein the body comprises a burnout elastic modulus(EMOD) of at least about 250 MPa.

Item 50. The abrasive article of item 49, wherein the first typeabrasive particles consist essentially of fused alumina.

Item 51. The abrasive article of item 49, wherein the first type ofabrasive particle comprises an average particle size of at least about500 microns and not greater than about 3000 microns.

Item 52. The abrasive article of item 49, further comprising a secondtype of abrasive particle different than the first type of abrasiveparticle, wherein the second type of abrasive particle comprises adifferent average particle size as compared to an average particle sizeof the first type of abrasive particle.

Item 53. The abrasive article of item 52, wherein the second type ofabrasive particle comprises an average particle size of at least about500 microns and not greater than about 3000 microns.

Item 54. The abrasive article of item 52, wherein the second type ofabrasive particle comprises zirconia and alumina.

Item 55. The abrasive article of item 49, wherein the body comprise ablend of the first type of abrasive particles and a second type ofabrasive particles different than the first type of abrasive particles,wherein the blend comprises a different amount (vol %) of the first typeof abrasive particle than an amount (vol %) of the second type ofabrasive particles, wherein the blend comprises a greater amount of thefirst type of abrasive particles than the amount of the second type ofabrasive particles, wherein the blend comprises a ratio (AP1/AP2) of atleast about 0.01 and not greater than about 4.

Item 56. The abrasive article of item 49, wherein the body comprises atotal content of abrasive particles of not greater than about 75 vol %for the total volume of the body, and at least about 30 vol %.

Item 57. The abrasive article of item 49, wherein the body comprises atotal content of bond material of not greater than about 70 vol % forthe total volume of the body, and at least about 25 vol %.

Item 58. The abrasive article of item 49, wherein the body comprisesporosity, wherein the body comprises a total content of porosity of notgreater than about 10 vol % for the total volume of the body.

Item 59. The abrasive article of item 49, wherein the bond materialcomprises a material selected from the group consisting of an inorganicmaterial, an organic material, and a combination thereof, wherein thebond material comprises an organic material selected from the groupconsisting of epoxy resins, polyester resins, polyurethanes, polyester,rubber, polyimide, polybenzimidazole, aromatic polyamide, modifiedphenolic resins, and a combination thereof, wherein the bond consistsessentially of a resin.

Item 60. The abrasive article of item 49, wherein the body furthercomprises a filler.

Item 61. The abrasive article of item 49, wherein the body is configuredto conduct a material removal operation on a workpiece comprisingtitanium, wherein the material removal operation is selected from thegroup consisting of cutting, grinding, finishing, and a combinationthereof.

Item 62. The abrasive article of item 49, wherein the burnout modulus ofrupture (MOR) of at least about 1.7 MPa, at least about 1.8 MPa, atleast about 1.9 MPa, at least about 2 MPa, at least about 2.1 MPa, atleast about 2.2 MPa, and not greater than about 10 MPa, not greater thanabout 8 MPa.

Item 63. The abrasive article of item 49, wherein the body comprises aburnout elastic modulus (EMOD) of at least about 270 MPa, at least about300 MPa, at least about 325 MPa, at least about 350 MPa, at least about375 MPa, at least about 400 MPa, at least about 425 MPa, at least about450 MPa, and not greater than about 1000 MPa, not greater than about 800MPa.

Item 64. An abrasive article comprising: a bonded abrasive bodyconfigured to work titanium comprising: a bond material; and a blend ofabrasive particles contained within the bond material, the blendcomprising: a first type of abrasive particles comprising fused alumina;and a second type of abrasive particles comprising zirconia.

Item 65. A method of working titanium comprising: providing a workpiececomprising titanium; and moving a bonded abrasive body relative to theworkpiece to conduct a material removal process on the workpiece,wherein the bonded abrasive body comprises a relative material removalrate (MRR) improvement of at least about 5% for a standard titaniumgrinding test as compared to a conventional abrasive article.

Item 66. The abrasive article of item 65, wherein the body comprises arelative material removal rate improvement of at least about 8%, atleast about 10%, at least about 12%, at least about 15%, and not greaterthan about 80%, not greater than about 50%, not greater than about 40%.

Item 67. The abrasive article of item 65, wherein the body comprises aburnout modulus of rupture (MOR) of at least about 1.6 MPa, at leastabout 1.7 MPa, at least about 1.8 MPa, at least about 1.9 MPa, at leastabout 2 MPa, at least about 2.1 MPa, at least about 2.2 MPa, and notgreater than about 10 MPa, not greater than about 8 MPa.

Item 68. The abrasive article of item 65, wherein the body comprises aburnout elastic modulus (EMOD) of at least about 250 MPa, at least about270 MPa, at least about 300 MPa, at least about 325 MPa, at least about350 MPa, at least about 375 MPa, at least about 400 MPa, at least about425 MPa, at least about 450 MPa, and not greater than about 1000 MPa,not greater than about 800 MPa.

Item 69. The abrasive article of item 65, wherein the body comprises arelative life improvement of at least about 5% for a standard titaniumgrinding test as compared to a conventional abrasive article, at leastabout 8%, at least about 10%, at least about 12%, at least about 15%,and not greater than about 80%, not greater than about 50%, not greaterthan about 40%.

Item 70. The abrasive article of item 65, wherein the body comprises afirst type abrasive particles consist essentially of fused alumina.

Item 71. The abrasive article of item 70, wherein the first type ofabrasive particle comprises an average particle size of at least about500 microns and not greater than about 3000 microns.

Item 72. The abrasive article of item 70, further comprising a secondtype of abrasive particle different than the first type of abrasiveparticle, wherein the second type of abrasive particle comprises adifferent average particle size as compared to an average particle sizeof the first type of abrasive particle.

Item 73. The abrasive article of item 72, wherein the second type ofabrasive particle comprises an average particle size of at least about500 microns and not greater than about 3000 microns.

Item 74. The abrasive article of item 72, wherein the second type ofabrasive particle comprises zirconia and alumina.

Item 75. The abrasive article of item 65, wherein the body comprise ablend of a first type of abrasive particles and a second type ofabrasive particles different than the first type of abrasive particles,wherein the blend comprises a different amount (vol %) of the first typeof abrasive particle than an amount (vol %) of the second type ofabrasive particles, wherein the blend comprises a greater amount of thefirst type of abrasive particles than the amount of the second type ofabrasive particles, wherein the blend comprises a ratio (AP1/AP2) of atleast about 0.01 and not greater than about 4.

Item 76. The abrasive article of item 65, wherein the body comprises atotal content of abrasive particles of not greater than about 75 vol %for the total volume of the body, and at least about 30 vol %.

Item 77. The abrasive article of item 65, wherein the body comprises atotal content of bond material of not greater than about 70 vol % forthe total volume of the body, and at least about 25 vol %.

Item 78. The abrasive article of item 65, wherein the bond materialcomprises a material selected from the group consisting of an inorganicmaterial, an organic material, and a combination thereof, wherein thebond material comprises an organic material selected from the groupconsisting of epoxy resins, polyester resins, polyurethanes, polyester,rubber, polyimide, polybenzimidazole, aromatic polyamide, modifiedphenolic resins, and a combination thereof, wherein the bond consistsessentially of a resin.

Item 79. The abrasive article of item 65, wherein the material removaloperation is selected from the group consisting of cutting, grinding,finishing, and a combination thereof.

Item 80. The abrasive article of item 64, wherein the bond materialcomprises a resin having a high temperature flexure modulus of at least1.05.

Item 81. The abrasive article of item 64, wherein at least one of typesof the abrasive particles has a cross-sectional shape as viewed in twodimensions comprising an ellipse, circle, triangle, rectangle, pentagon,hexagon, heptagon or octagon.

EXAMPLES Example 1

The body of the abrasive articles of the embodiments herein may haveparticular performance properties, including for example, a materialremoval rate (MRR). For example, according to one aspect, the bodycomprises a relative material removal rate (MRR) improvement of at leastabout 5% for a standard titanium grinding test as compared to aconventional abrasive article. The material removal rate test wasconducted according to the following conditions. Material removal (inpounds) is calculated by the difference between the start and finalweights of the grinded material (e.g., titanium slabs). During grinding,the contact time is monitored while the grinding wheel and material isin contact. Then, material removal rate (MRR, lbs/hr) can be calculatedas material removal (lbs) divided by contact time (hr). As shown inTable 1, the conventional abrasive article and the inventive wheelcomprised the following:

TABLE 1 Conventional Wheel Exemplary Wheel MATERIAL VOL % MATERIAL VOL %ZF-grit 6 27 ZF-grit 6 22 ZF-grit 8 9 57A-grit 6 9 ZF-grit 10 9 ZF-grit8 7 30 grit fine 13 57A-grit 8 3 29-722 resin 24 ZF-grit 10 7 saran 157A-grit 10 3 CAM 9 30 grit fine 11 0 Exemplary resin 22 0 0 Saran 1LIME 4 CAM 7 0 0 0 0 0 0 LIME 3 0 0 0 0 0 0 0 chop strand fiber 4 0 0 0chop strand fiber 4

The test conditions appear in Table 2.

TABLE 2 Condition Setting Wheel Size 25 × 4 × 12″ Stub Size Fine Centersize ~15.5″ Material Shape Rectangular and octagon Titanium billetsWheel Speed 1955 Crossfeed 0.75 in Traverse speed 272 fpm Grindingpressure 1100 psi Grind angle 90°

The test results are displayed in Table 3.

TABLE 3 Relative MRR Con- Material com- Material tact Removal paredWheel Removal time Rate Average to Specification number (lbs) (hr) (MRR)MRR STD STD 526 1.18 445.76 445.76 — NEW SPEC 1 556 1.06 524.53 528.5018.56% 2 622 1.08 575.93 3 616 1.27 485.04

In some instances, the relative material removal rate improvement can beat least about 8%, at least about 10%, at least about 12%, or even atleast about 15%. Still, in at least one embodiment, the relativematerial removal rate improvement may be not greater than about 80%,such as not greater than about 50%. It will be appreciated that therelative material removal rate improvement of the body can be within arange between any of the minimum and maximum percentages noted above.

In addition to the relative improvement in material removal rate, thesame test procedure demonstrates an improvement in life of the articleover conventional abrasive articles. Life improvement may becharacterized by Q ratio, which is the amount of metal removal dividedby the amount of wheel wear. For example, according to one embodiment,the body can have a relative life improvement of at least about 5% for astandard titanium grinding test as compared to a conventional abrasivearticle under the conditions noted above for relative material removalrate improvement. In another embodiment, the relative life improvementcan be at least about 8%, such as at least about 10%, at least about12%, or even at least about 15%. Still, in at least one non-limitingembodiment, the relative life improvement can be not greater than about80%, such as not greater than about 50%. It will be appreciated that therelative life improvement of the body can be within a range between anyof the minimum and maximum percentages noted above.

Example 2

Two general abrasive articles are made including a general conventionalsample (CS1) and an inventive first sample (S1) representative of anembodiment herein. Samples CS1 and S1 are grinding wheels constructed asdescribed above in Table 1.

Various specific samples if CS1 were made, wherein the content ofalumina-zirconia grains is substituted for a particular content of fusedalumina grains commercially available as 57A from Washington Mills.Notably, three distinct specific examples of the general conventionalsamples CS1 is made, wherein the first specific sample (CS1a) having 0vol % of 57A abrasive grains, a second specific sample (CS1b) having15.5 vol % of 57A abrasive grains, and a third specific sample (CS1c)having approximately 52 vol % of 57A abrasive grains.

Various specific samples if S1 are made, wherein the content ofalumina-zirconia grains is substituted for a particular content of fusedalumina grains commercially available as 57A from Washington Mills.Notably, two distinct specific examples of sample S1 are made, whereinthe first specific sample (S1a) has 0 vol % of 57A abrasive grains, anda second specific sample (Sib) has 15.5 vol % of 57A abrasive grains

FIG. 1 includes a plot of relative performance versus content of aparticular type of abrasive particle for the three specific conventionalsamples and specific samples representative of embodiments herein. Thetest conditions were the same as those described above in Table 2. Asillustrated, for the specific conventional samples (CS1a, CS1b, andCS1c) with increasing content of fused alumina grains, the relativeperformance of the abrasive article decreases. By contrast, the relativeperformance of samples S1a and S1b is dramatically improved over all ofthe specific conventional samples. Sample S1b demonstrates a relativeperformance improvement of over 40% compared to sample CS1b.

FIG. 2 is a plot of relative material removal rate versus content of aparticular type of abrasive particle for a conventional sample and asample representative of an embodiment herein. The test conditions werethe same as those described above in Table 2. As illustrated, for thespecific conventional samples (CS1a, CS1b, and CS1c) with increasingcontent of fused alumina grains, the relative material removal rate ofthe abrasive article decreases. By contrast, the relative materialremoval rate of samples S1a and S1b is dramatically improved over all ofthe specific conventional samples. In fact, Sample S1b demonstrates arelative material removal rate improvement of approximately 40% comparedto sample CS1b.

Example 3

FIG. 3 is a Weibull probability plot for a particle crush strength testof two samples, S11 and S12. For this test, the test frame was MTSSintech 2/G, the test method was single particle crush, the fixture hadcarbide platens with a load cell of 1000 lbs, and the test speed was 2μm/sec. The single particle crush test was conducted on a Sintech 2/Gmachine, commercially available from MTS Corporation. A 6 grit-sizeparticle was prepared and placed between two platens of polycrystallinediamond. A 1000 lb load cell was selected for a compression method testusing Testworks software on the Sintech 2/G machine. The compressiontest was initiated by selecting a test speed of 2 microns/second and apre-load of less than 2 N. The test is completed when the particle issufficiently fractured under the load cell and the force necessary tofracture is determined by the Sintech 2/G machine. At least 30 particleswere tested and a Weibull plot was generated, such as the plotillustrated in FIG. 3, herein.

The sample S12 is alumina 57A. The sample S11 is zirconia grain ZF. Thehorizontal x-axis depicts the force (in newtons) required to break thegrains. The vertical y-axis depicts the percentage of the grains brokenwhen subjected to breaking force. A 95% confidence interval (CI) isindicated by the lines surrounding each of the two sets of plotted data.To compare the grain crush strength of each sample, representativemeasurements may be made at both 50% of the grains broken, and at 90% ofthe grains broken. For example, at the 50% interval, the lower 95%confidence interval for S12 is about 220 N, and the upper 95% confidenceinterval for S12 is about 280 N. Also at the 50% interval, the lower 95%confidence interval for S11 is about 1800 N. Thus, at a minimum, S12 hasa lower grain crush strength than S11 by about(1800−280)/1800=1520/1800=84%. At the other extreme of the 50% interval,the upper 95% confidence interval for S11 is about 2100 N, and the lower95% confidence interval for S12 is about 220 N. Also at the 95%interval, the upper 95% confidence interval for S11 is about 2100 N.Thus, at a maximum, S12 has a lower grain crush strength than S11 byabout (2100−220)/2100=1880/2100=90%.

At the 90% interval, the lower 95% confidence interval for S11 is about2300 N, and the upper 95% confidence interval for S12 is about 400 N.Thus, at a minimum, S12 has a lower grain crush strength than S11 byabout (2300−400)/2300=1900/2300=83%. At the other extreme of the 90%interval, the upper 95% confidence interval for S11 is about 2900 N, andthe lower 95% confidence interval for S12 is about 300 N. Thus, at amaximum, S12 has a lower grain crush strength than S11 by about(2900−300)/2900=2600/2900=90%. Thus, sample S12 is more friable thansample S11.

Example 4

Table 4 comprises data for grain toughness and hardness tests of thesame two samples in Example 2, S11 and S12. The toughness test methodwas K1C by indentation fracture. Each grain was encapsulated in epoxy,polished to provide a flat surface, and then the flat surface wasindented. The input parameters were a load of 0.5 kg and elastic modulusof 410 GPa.

TABLE 4 Toughness Hardness K1C in MPa m^(1/2) Hv in GPa S12 2.06 +/−0.20 16.99 +/− 0.47 S11 3.39 +/− 0.16 15.22 +/− 0.43

In terms of toughness, sample S12 has a K1C of 2.06+/−0.20 MPa m^(1/2)(or max 2.26 and min 1.86). Sample S11 has a K1C of 3.39+/−0.16 MPam^(1/2) (or max 3.55 and min 3.23). Thus, at a minimum, S12 has a lowergrain toughness than sample S11 by about (3.23−2.26)/3.23=0.97/3.23=30%.At a maximum, S12 has a lower grain toughness than S11 by about(3.55−1.86)/3.55=1.69/3.55=48%.

In terms of hardness, sample S12 has a Hv of 16.99+/−0.47 GPa (or max17.46 and min 16.52). Sample S11 has a Hv of 15.22+/−0.43 GPa (or max15.65 and min 14.79). Thus, at a minimum, S11 has a lower hardness thanS12 by about (16.52−15.65)/16.52=0.87/16.52=5%. At a maximum, S11 has alower hardness than S12 by about (17.46−14.79)/17.46=2.67/17.46=15%.

The processes and abrasive articles disclosed herein represent adeparture from the state-of-the-art. Abrasive articles herein canutilize a combination of features, including but limited to, certaintypes of abrasive particles, particular blends of abrasive particletypes, porosity, bond material, content of bond material, content ofabrasive particles, content of abrasive particle types, relativeperformance improvement, relative material removal rate improvement, anda combination thereof. While not entirely understood, the combination offeatures facilitates the formation of abrasive articles that havedemonstrated unexpected and remarkably improved performance over stateof the art abrasive articles.

The above-disclosed subject matter is to be considered illustrative, andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments, which fall withinthe true scope of the present invention. Thus, to the maximum extentallowed by law, the scope of the present invention is to be determinedby the broadest permissible interpretation of the following claims andtheir equivalents, and shall not be restricted or limited by theforegoing detailed description.

The Abstract of the Disclosure is provided to comply with Patent Law andis submitted with the understanding that it will not be used tointerpret or limit the scope or meaning of the claims. In addition, inthe foregoing Detailed Description of the Drawings, various features maybe grouped together or described in a single embodiment for the purposeof streamlining the disclosure. This disclosure is not to be interpretedas reflecting an intention that the claimed embodiments require morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive subject matter may be directed toless than all features of any of the disclosed embodiments. Thus, thefollowing claims are incorporated into the Detailed Description of theDrawings, with each claim standing on its own as defining separatelyclaimed subject matter.

What is claimed is:
 1. An abrasive article configured to work titaniumcomprising: a body including: a bond material comprising a resin havinga high temperature flexure modulus of at least 1.05; and a first type ofabrasive particles contained within the bond material comprising fusedalumina.
 2. The abrasive article of claim 1, wherein the first typeabrasive particles consist essentially of fused alumina.
 3. The abrasivearticle of claim 1, wherein the first type of abrasive particlecomprises an average particle size of at least about 200 microns.
 4. Theabrasive article of claim 1, further comprising a second type ofabrasive particle different than the first type of abrasive particle. 5.The abrasive article of claim 4, wherein the second type of abrasiveparticle comprises an average particle size of at least about 200microns.
 6. The abrasive article of claim 4, wherein the second type ofabrasive particle comprises at least about 60% and not greater thanabout 95% alumina, and at least about 5% and not greater than about 40%zirconia.
 7. The abrasive article of claim 1, wherein the body comprisea blend of the first type of abrasive particles and a second type ofabrasive particles different than the first type of abrasive particles,wherein the blend comprises a different amount (vol %) of the first typeof abrasive particle than an amount (vol %) of the second type ofabrasive particle.
 8. The abrasive article of claim 7, wherein the blendcomprises a ratio (AP1/AP2) of at least about 0.01 and not greater thanabout 4, wherein AP1 represents the weight of first type of abrasiveparticles in the blend and AP2 represents the weight of the second typeof abrasive particles in the blend.
 9. The abrasive article of claim 1,wherein the body comprises a total content of abrasive particles of notgreater than about 75 vol % and at least about 30 vol % for a totalvolume of the body.
 10. The abrasive article of claim 1, wherein thebody comprises a total content of bond material of not greater thanabout 70 vol % and at least about 25 vol % for the total volume of thebody.
 11. The abrasive article of claim 1, wherein the body comprises atotal content of porosity of not greater than about 10 vol % and atleast about 0.05 vol % porosity for a total volume of the body.
 12. Theabrasive article of claim 1, wherein the bond material comprises anorganic material selected from the group consisting of epoxy resins,polyester resins, polyurethanes, polyester, rubber, polyimide,polybenzimidazole, aromatic polyamide, modified phenolic resins, and acombination thereof.
 13. The abrasive article of claim 1, wherein thebody further comprises a filler comprising a material selected from thegroup consisting of powders, granules, spheres, fibers, sand, bubblealumina, bauxite, chromites, magnesite, dolomites, bubble mullite,borides, titanium dioxide, carbon products (e.g., carbon black, coke orgraphite), wood flour, clay, talc, hexagonal boron nitride, molybdenumdisulfide, feldspar, nepheline syenite, glass spheres, glass fibers,CaF₂, KBF₄, Cryolite (Na₃AlF₆), potassium Cryolite (K₃AlF₆), pyrites,ZnS, copper sulfide, mineral oil, fluorides, carbonates, calciumcarbonate, and a combination thereof.
 14. The abrasive article of claim1, wherein the body is configured to conduct a material removaloperation on a workpiece comprising titanium.
 15. The abrasive articleof claim 1, wherein the body comprises a burnout modulus of rupture(MOR) of at least about 1.6 MPa and not greater than about 10 MPa. 16.The abrasive article of claim 1, wherein the body comprises a burnoutelastic modulus (EMOD) of at least about 250 MPa and not greater thanabout 1000 MPa.
 17. The abrasive article of claim 1, wherein the bodycomprises a relative material removal rate (MRR) improvement of at leastabout 5% and not greater than about 80% for a standard titanium grindingtest as compared to a conventional abrasive article.
 18. The abrasivearticle of claim 1, further comprising a second type of abrasiveparticle different than the first type of abrasive particle, wherein thefirst type of abrasive particle is at least about 50% more friable thanthe second type of abrasive particle.
 19. The abrasive article of claim1, wherein to break 90% of the first type of abrasive particles, atleast about 300 N and no greater than about 1500 N is required.
 20. Theabrasive article of claim 1, further comprising a second type ofabrasive particle different than the first type of abrasive particle,wherein to break 90% of the second type of abrasive particles, at leastabout 500 N and greater than about 3300 N is required.